Get rid of your findAll declaration in jaws.xml. If you have findAll() in the home interface of ComponentEnt, JAWS should implement it for you. This may be the problem. Also, even though you are inheriting the implementation of PartEnt, I don't think it will inherit the field to db mapping in jaws.xml. If JBoss can do this, it's probably not portable. So, you will probably have to map the fields for ComponentEnt in jaws.xml